Blue shark liver oil (Prionace glauca): Fractionation and stabilization with antioxidants

Abstract

Crude oil was obtained by boiling (75°C /15 min) mashed livers of the blue shark (Prionace glauca). The crude oil was dry fractionated and the oxidative stability of both the crude oil and it's fractions (olein and stearin) was evaluated using the Rancimat method (80°C; 2.5 g sample; 20L/h air flow). The efficiency of the following antioxidants, Butylated Hydroxy Toluene (BHT), Tertiary Butyl Hydroquinone (TBHQ), Ascorbil Palmitate (PA), ANTRACINE 220 (TBHQ + citric acid). TOCOMIX D (α and γ tocopherols) and RENOXAN A (Ascorbil Palmitate + Lecitin + α tocopherol), were tested in various concentrations. The concentration of polyunsaturated fatty acids was 28% in the whole crude oil; 24% in the stearin fraction and 33% in the olein; the oxidative stability was inversely related to the content of polyunsaturated fatty acids. TBHQ was the most efficient antioxidant in crude oil as well as in the fractions. Treatment with the natural antioxidant RENOXAN A was also highly efficient, though less so than TBHQ.